What Makes Concrete a Sustainable Building Material?

By Anne Balogh

Concrete Batch Plant. Davis Colors.

This parking lot installed in 2001 at Bannister Park, Fair Oaks, Calif., is the first in the state to use pervious concrete. The Sacramento Cool Communities program was a partner in the project, which used pervious concrete for stormwater management and to reduce the urban heat-island effect. In about 10 years, the trees will shade more than half the lot.

Concrete is a friend of the environment in all stages of its life span, from raw material production to demolition, making it a natural choice for sustainable home construction. Here are some of the reasons why, according to the Portland Cement Association and the Environmental Council of Concrete Organizations:

Resource efficiency. The predominant raw material for the cement in concrete is limestone, the most abundant mineral on earth. Concrete can also be made with fly ash, slag cement, and silica fume, all waste byproducts from power plants, steel mills, and other manufacturing facilities.

Durability. Concrete builds durable, long-lasting structures that will not rust, rot, or burn. Life spans for concrete building products can be double or triple those of other common building materials.

Thermal mass. Homes built with concrete walls, foundations, and floors are highly energy efficient because they take advantage of concretes inherent thermal massor ability to absorb and retain heat. This means homeowners can significantly cut their heating and cooling bills and install smaller-capacity HVAC equipment.

Reflectivity. Concrete minimizes the effects that produce urban heat islands. Light-colored concrete pavements and roofs absorb less heat and reflect more solar radiation than dark-colored materials, such as asphalt, reducing air conditioning demands in the summer.

Ability to retain stormwater. Paved surfaces tend to be impervious and can block natural water infiltration into the soil. This creates an imbalance in the natural ecosystem and leads to problems such as erosion, flash floods, water table depletion, and pollution. Pervious concrete is a special type of structural concrete with a sponge-like network of voids that water passes through readily. When used for driveways, sidewalks, parking lots, and other pavements, pervious concrete can help to retain stormwater runoff and replenish local water supplies.

Minimal waste. Concrete can be produced in the quantities needed for each project, reducing waste. After a concrete structure has served its original purpose, the concrete can be crushed and recycled into aggregate for use in new concrete pavements or as backfill or road base.